Fix bug #81491: Ensure HAVE_ARGON2LIB is set when compiling using libargon2

Closes GH-7538.

Author: mallardduck

NEWS

@@ -7,6 +7,10 @@ PHP                                                                        NEWS
     Doleček)
   . Fixed bug #81380 (Observer may not be initialized properly). (krakjoe)
 
+- Standard:
+  . Fixed bug #81491 (Incorrectly using libsodium for argon2 hashing).
+    (Dan Pock)
+
 - Streams:
   . Fixed bug #81475 (stream_isatty emits warning with attached stream wrapper).
     (cmb)

ext/standard/config.m4

@@ -407,6 +407,8 @@ if test "$PHP_PASSWORD_ARGON2" != "no"; then
   PKG_CHECK_MODULES([ARGON2], [libargon2])
   PHP_EVAL_INCLINE($ARGON2_CFLAGS)
   PHP_EVAL_LIBLINE($ARGON2_LIBS)
+
+  AC_DEFINE(HAVE_ARGON2LIB, 1, [ ])
 fi
 
 dnl